The creation of compelling and high quality packaging for consumer durables is well established and is executed in a variety of forms and formats known in the prior art; however each of the prior art formats and methodologies have their own particular limitations. The consumer market demands increasing colour, vibrancy and novelty in addition to sophistication in order to provide eye catching shapes that will serve to differentiate products available for sale in a given marketplace. In addition to such aesthetic considerations an element of physical protection is also required for the goods in question. Such physical requirements of the packaging in question, often require complex internal structures or substructures to protect the packaged product which can introduce considerable cost and complexity to the packaging products commonly available.
The core packaging functions to contain, protect, preserve and promote the products in question, are often offset by substantial cost and lack of sustainability. The materials used are often from a non-renewable sources, or manufactured with processes that causes harmful environmental emissions, or in such a way as to preclude recycling and re-use. The cost of packaging can add considerably to the final cost of a product as it enters commerce and it is desirable to provide the best packaging possible at the most economical cost. Sustainability is also another key issue and an increasingly politicised issue of keen interest in the minds of consumers who may consider the type of packaging used for a product as part of any “buying decision”. In addition, there is a general move and sympathy towards the provision of legislation and guidelines against non-sustainable packaging of consumer products.
The commonly available packaging techniques and materials can be summarised as follows:
Paper And Cardboard
Paper or Cardboard packaging is the most common form of packaging found in the market today. Paper and cardboard packaging is low cost and has the ability to accept printing and finishing to a very high standard but has a principal restriction by limitation of its form. Card is printed and then folded so as to create boxes or constructions limited by largely planer configurations. The inability to readily conform cardboard to other than linear and planer shapes does not allow this material to be adapted for brand or product discrimination in the marketplace as all packaging based on cardboard incorporates substantial planar elements. The ubiquitous nature of cardboard also means that it is difficult for suppliers to create perceived value around the product without resorting to complicated treatments of the boxes, including lamination and use of metallic and plastic films etc. The more complicated the printing and laminating and/or folding involved in any manufacture of a packaging product, the more costly the end product results which must be passed onto the consumer. In addition, a number of the perceived high quality treatments in cardboard and paper packaging, require the use of processes that are not environmentally sustainable, or which hinder the recycling of the packaging and therefore make the packaging less environmentally friendly than it otherwise could be.
Use of recycled materials is also limited by a reduction in strength of cardboard; the main process used for packaging materials is the Fourdrinier process. This process creates a flat sheet of material where fibres are aligned in the direction of the production flow, giving rise to distinct properties within the finished board, which can be used to either increase the compression strength of the board or its flexibility. These particular features are compromised by the use of recycled pulp because of the changes occurring in the pulp particles during recycling processes. In addition, legislation governs the application and use of recycled materials in this process due to hygiene issues.
Plastic is a highly creative medium allowing for the development, design and creation of packaging shapes that are unique, individual and include curves, compound curving or organic forms and which may in turn produce an enormous range and configuration of packaging and presentations, thereby allowing the branding of a particular product or the shape of the actual container to be used as powerful marketing and branding tools. Plastics are able to be brightly coloured and have the ability to take up print and decoration across compound surfaces to give a similar result to that of moulded metal but at a much lower cost. Plastics can be decorated by a number of means; direct printed, labelled or in-mould labelled. This latter process involves the insertion of a polymer label into the empty plastic forming mould, the label is robotically placed and as it is a planar printed label is positioned on a planar section of the tool. The plastic material is introduced and the surface of the plastic product fuses with the label material to create a smooth decorated surface. This technique of “in mould labelling” is well known and creates interesting and unique packages for use with a variety of goods.
A key limitation and drawback with plastic packaging is the non-sustainability of this packaging methodology and an increasingly poor consumer perception of the throwaway and disposable nature of plastic packaging. Most thermo-plastics are derived from oil and as such the price of this commodity is invariably increasing, in addition to the perception of the non-renewable nature of this commodity, it suffers a generally poor public perception. Most thermo plastics are readily recycled, although the variety of plastics complicates the sorting process. The recycled material is classed as re-grind material and as such its use is more limited than virgin material. This is most notable in the products that have direct food contact were the use of regrind material is not permitted or in some cases it has to be the external material, tied to the inner which is virgin plastic.
An increasing use of organically-derived plastics to address some of the environmental concerns are provided for in the prior art, however, organically-derived materials can also have problems, in particular the so called “bio-polymers”, which may not be as sustainable as they first appear. Most first generation bio-polymers are derived from polylactic acid and this material is not catered to in the current plastic recycling methodologies. In addition, polylactic acid is not compatible with petroleum based plastics and is generally considered a contaminant. In addition, the current rationale understood with respect to bio-polymers is that they are compostible and so can be added to landfill. However the energy required in their creation is not returned or reduced by this process and in a number of cases, polylactic acid is inferior and/or requires more material to equal the performance of petroleum based plastics.
Glass
Clarity, strength and substance as well as premium perception has kept glass a first choice material for a number of high end products including perfumes, skin care products etc where the weight of the glass and its inherent coolness serves to enhance the perception of quality. However glass as a packaging medium, is heavy, fragile and requires a lot of energy to melt and reform.
Metal
Pressed metal boxes and tins are often used in consumer packaging because they can be brightly coloured and formed into a number of eye catching shapes, including curved and organic shapes.
Metal can be formed either by welding into cylinders or through impact moulding. Impact moulding involves the use of a flat sheet of metal which is formed between two shaped metal dyes which subject the metal to a high impact and forces the flat sheeted material to conform to the profile of the dye.
The deformation of metal during this process, whilst it can be severe, generally with respect to the artwork applied to metallic boxes and tins, deformation is of little concern and the artwork can be readily applied to the flat sheet of material in a pre-distorted form which then goes through the moulding process and deforms with the metal such that the requisite imagery or graphics are rendered onto the final product.
Metal itself is however an expensive raw material and in comparison to paper, the unit cost of a metallic container is far greater than the similar piece of packaging made from plastic or cardboard. The use of metallic boxes and packaging is generally less sustainable than the previously described materials and requires substantial energy for recycling. In addition, the use of metallic materials for packaging involves the use of a finite resource and the mining industry and forging of metals for packaging is increasingly being perceived by the consuming public as environmentally questionable.
Pulp Fibre
Formed pulp paper has a restricted and limited public perception at this point in time due to its principal association with low end single colour products like fruit trays or egg boxes. The fibre used in the preparation of pulping products can be the same which is used in typical paper production but it is also possible to use fibres derived from products other than wood. The development of pulp fibre processing in its simplest form involves a creation of a mat of fibres by lifting a mesh through a vat of fibres in suspension. The fibres are then collected by the mesh and excess water drains away. The positively shaped mesh is then brought into contact with the negatively shaped mould and subsequently heated with the application of pressure to remove excess water. The process then dries the mat into its final form. The currently used single stage processes generally give pulp a distinctive coarse finish with the marks of the mesh clearly visible as witnesses on one or more of the faces.
Modern high pressure pulp thermoforming has provided many improvements to the previously described single stage process. Modern high pressure pulp thermoforming generally involves a two stage forming process which can result in high quality finished products with a smooth finish which is comparable to that of high quality flat cardboard. The modern two stage pulp thermoformer works in such a way that the pulp is moulded over the extraction mesh then transferred to a conventional solid male-female mould with extraction vents. The mould is then heated to about 200° and steam extracted through vents in the mould by vacuum which results in a dense, smooth finish product that can be curved or contain multiple compound curves.
The benefits of pulp as a packaging medium include low cost and the ability to conform the product into a wide variety of highly complex compound shapes. The added benefit of pulp as a packaging medium include the ability for the product to be solid coloured right through with the use of dyes in the pulp vat. In addition, the material can have variable wall thickness depending on the specific localised pressure used at the point of forming which gives excellent insulation properties for heat and shock.
The key disadvantage of pulp fibre packaging from a commercial point of view is the limitation to the use of a single colour throughout the packaging material. In addition, once the pulping material has been formed and dried into the final moulded shape, it is not possible to economically print upon or decorate such surfaces.
Whilst it is possible to place adhesive stickers on such packaging, adhesive stickers are only able to be applied economically to planar surfaces which provide distinct limitations to the form and design of such packaging products. In addition, adhesive stickers are not visually appealing because they are not fully integrated with the design and manufacture of the product and the application of adhesive labels requires precision and specific care in alignment and places limitations on any high speed industrial process. A further technique for use with pulp fibre packaging includes the use of vacuum or heat to form a laminated plastic film over the finished dried packaging product complete with compound curves. However, such films have disadvantages including their appearance as add-ons or additions and distraction from the integrated perception of the whole design; such products are also limited by the compound nature of the surface to which they can adhere where extremely deep valleys or ridges are not possible without the film ripping or folding which compromises the final product; and finally, the nature of the adhered film is such that it is necessarily a plastic adhered to paper pulp which then compromises recycling and sustainability.
Moulded pulp products are well known, particularly as both internal and external packaging products. For example, moulded pulp egg crates, or cartons have been used for decades for packaging eggs. Similar packaging products are used for a variety of fruit and vegetables and other products that require protection during transportation. Computer components, printer cartridges, vehicle components and many other products are packaged using moulded pulp packaging. Moulded pulp is used for containers for plants in plant nurseries.
The pulp for such packaging is conveniently and cheaply manufactured from waste paper and other waste material. In one process, a pulp slurry is prepared from waste paper, cardboard, textiles and other similar waste material. The slurry may include additives of any type, including, but not limited to, chalk and fabric material. Such additives impart desirable characteristics to the finished product. For example, chalk added to the pulp slurry results in a product having a china-like feel, while the addition of fabric to the slurry results in a product having a quality fabric feel.
In producing a product of moulded pulp, a mould is prepared for the product to be made. A mat of pulp is lifted from the slurry container, generally using a framed mesh, and is deposited into the preliminary mould. The thickness of the pulp mat is determined by the relative speed of the framed mesh dip into the slurry container, and subject to the fibre and moisture content of the pulp slurry. The mat is placed into the mould and pressure or heat and pressure is applied to remove the water content and force the pulp and mat to adopt the shape of the mould.
With products of this type, printing or other decoration may be applied only to any planar surfaces or surfaces that contain only two dimensional curves, such as cylindrical or conical surfaces or the like.
The conventional moulding process is divided preferably into two parts, where the pulp is moulded and formed twice, in two separate and different moulds. A preliminary mould is prepared for the product to be made. The preliminary mould is designed to be within predetermined tolerances, shapes and dimensions of the final mould shape as there is a limited elasticity in a preliminary moulded pulp pre-form for the subsequent moulding stage.
A mat of pulp is lifted from the slurry container, preferably by a framed mesh, which is itself shaped to be the opposing part of the preliminary mould and is offered up into the preliminary mould. The thickness of the pulp mat is determined by the relative speed of the framed mesh dip into the slurry container, and subject to the fibre type, consistency of the slurry and moisture content of the pulp slurry.
The mat is formed into a pre-form shape in the preliminary mould by applying heat and pressure. A vacuum is applied to the rear of the mesh to facilitate the extraction of water content form the pulp in the form of steam. This process sets the overall material parameters of the pulp and the initial characteristics of the product shape. These characteristics include the volume of pulp in the product, uniformity of wall thickness, initial density and dimensional size. These characteristics are calculated to allow for specific tolerances in specific areas, such that those areas that will be subjected to deformation in the secondary moulding process are left with higher moisture contents and lower particle density, so that the pulp retains elasticity at this point. During this stage of the moulding process, an amount of the moisture content of the pulp slurry is removed from the mat. When the pre-form has been formed by and to the desired shape by the preliminary mould, preferably using pressure or heat and pressure, the pre-form is removed therefrom and transferred to a final mould which will impart the final product shape to the pre-form. The final shape may involve the provision of ribs, areas of different thicknesses, areas of different densities, complex curved shapes, planar surfaces and many other different features. The development of such features may be the function of differing heat and pressure applications, and over varying times, calculated to give the desired characteristics for the moulded pulp product. Accordingly, levels of rigidity, dryness, insulation, barrier properties and other properties may vary within a product and between products.
Thus, for any given product design, the pre-form and final form moulds will involve designing the moulds to apply different amounts of heat and pressure in different locations to create areas of differing shapes, thicknesses and densities in walls, differing rib and fin densities, and other product shape characteristics in order, for example, to retain or disburse heat (as an insulator) or physical shock, as required by the end product.
The moulded product is formed in two stages as outlined above, and the printing is applied to the pulp after the first moulding process, but before the second moulding process by a printing process. The printing is designed so that, during the final moulding process, the printed material, when conformed to the final complex moulded shape, presents an image which may be easily identified, read and understood, or scanned. Decoration, in the form of embossing, raised or depressed areas which accentuate or complement the printing may occur either in the preliminary or secondary moulding, in both, or progressively, that is the same areas partially raised or depressed in the preliminary moulding are then further depressed or raised in the secondary moulding. Thus, the printing and decorating that occurs on the pre-form prior to forming the final shape is formed into identifiable indicia, logos, recognisable printing or recognisable decoration when the pre-form is subsequently processed in the final mould to its final shape.
Products from such processes may take the form of a complex shape, such as a food container in the shape of an animal head, such as the head of a monkey. With such a product, the pre-form may be in the shape of two connected parts of a polyhedral having multiple planar surfaces each of which can be easily printed with a decoration or design. During final moulding, the printed polyhedral halves are formed into the lower and upper head shapes of multiple, complex curves in the shape of, for example, a monkey's head, and the printed surfaces take the shape, form and appearance of the facial features of the monkey's head, including eyes, nose and ears. The edges of each container half are designed to meet and are shaped and printed in the form of the mouth. Such a novel container may have many uses in the food industry, such as a container for takeaway food products, confectionery, or the like; or as packaging for a wide variety of personal care goods such as perfume and toiletries.
Products made in accordance with these techniques may take any shape or form that is able to be moulded using pulp moulding techniques. Thus, high quality moulded pulp products with sophisticated printing and decoration may be produced relatively cheaply to replace products of other relatively expensive materials such as synthetic plastics.
The design of the print or decoration to be applied to the two dimensional surfaces of the pre-form is developed so that, when the surfaces are moulded to complex curves, the printing and/or decoration takes up a desired appearance, which may be in the form of printed letters, pictures, logos or other indicia. The printing is therefore designed to be developed, on moulding from a planar to a curved shape, to the required finished appearance of lettering or the like, including barcodes or other product identification information. During the moulding process, the printed material on the planar or two dimensional curved surfaces morphs or transmutes into the shapes and appearance on the complex curved shapes on the moulded surfaces to display the desired finished appearance. Thus, the printing may expand or contract with the change in the shape of the surface on which it is printed.
The inks or other fluid, or powder, that are used for the printing are selected from inks, powders or fluids having the necessary elasticity, colour depth, high drawing and opaqueness to be able to deform, during moulding, without colour change, separation and undesired intensity variation. The ink or other coating compound must also be able to withstand the pressures and heat used during the secondary moulding stage. The processes described above are particularly relevant to designs with lettering, barcodes, logos and the like on the finished moulded product. This may use an anamorphic projection to modify the aspect ratio of the finished graphic design by optical distortion to stretch or compress the image in various dimensions so that the design is faithfully reproduced in the finished form from a distorted initial image printed on the two dimensional surfaces. A computer assisted design program may be used to transfer the design directly or through the more traditional reprographic methods onto a carrier film, into an automated printing machine or print spray machine as required by the end product design. An optimum target point of decoration on the pre-form is identified, using a deformation grid to ensure that the anamorphic distortion is able to be distorted to a predictable extent during final moulding.
The surfaces of the pre-form to which printing is to be applied, which surfaces may be planar or curved in one direction, such as part cylindrical or conical surfaces, can have the printing applied thereto by one or more of many known printing processes.
However, the previously described methods involve complex techniques to faithfully reproduce the required images on the final product. In addition, the previously described printing methods rely on silicon coated paper or polymer web to carry the printing and apply the printing in one off applications of the printing to the pre-form which greatly limits the speed of manufacture and limits the options for automation.
It would be desirable to provide an alternative to current packaging processes and techniques utilising the advantages of pulp fibre providing such packaging can be provided with a high finished quality and with the ability to receive high definition printing and decoration as found in the previously detailed prior art products.
Accordingly, one object of the invention is to provide an improved method and apparatus for moulding and printing pulp fibre materials.
For the purposes of this specification, the term “pulp material” shall be taken to mean pulp formed of a mixture of cellulose fibres, including, but not limited to, cellulose fibres derived from waste and other paper, cardboard, yarns and textiles, plant fibres including wood chips and other timber and plant material including waste, and any other material predominately of cellulose. The term “printing” shall be taken to include printed decoration of all forms and dried printed decoration. The term “intermediate transfer surface shall be taken to include all variations and vehicles used to apply the print decoration to the pulp including variations where a) the intermediate transfer surface is a part of the physical apparatus used to perform the invention, in the manner of a roller which handles the printed decoration temporarily prior to applying same to the pulp; and b) where the intermediate transfer surface takes the form of a carrier of the print decoration that is integrated, along with the print decoration, by melding into the pulp so as to form a physical part of the pulp and final product.